EastEnders viewers were treated to a last-minute shock tonight as Sam Mitchell made a surprise return to Albert Square, and, in classic Walford fashion, it happened just seconds before the credits rolled. No warnings, no dramatic confrontation, no fiery comeback speech. She simply stepped back onto the Square as if she’d only popped out for a quick break, instantly reminding everyone that the Mitchells are never quiet for long.

And while tonight revealed absolutely nothing about why she’s back or what she’s planning, viewers won’t have to wait long before the truth starts to unravel.

For now, all we saw was the return, not the fallout. Sam didn’t speak to anyone, wasn’t spotted by any familiar faces and didn’t hint at the trouble brewing beneath the surface. But her calm walk across the Square was very much the calm before the storm, and upcoming episodes are set to lift the lid on the real reason she’s returned home.

EastEnders has already confirmed that Sam’s comeback will lead to a major storyline centred around her health. Viewers will soon learn that Sam has secretly found a lump in her breast, a discovery that leaves her terrified and desperate to hide the truth. She returns to Walford determined not to tell a soul, but her panic and strange behaviour will quickly raise eyebrows among the people who know her best.

In the coming weeks, Phil, Jack and Denise will all begin to notice that something is off, and their attempts to get through to her will gradually push Sam toward seeking medical help. Eventually, Sam will receive a breast cancer diagnosis, caught at an early stage, and will undergo treatment in the New Year. The soap is working closely with Breast Cancer Now to ensure the storyline is portrayed sensitively, accurately and with a clear message about the importance of checking for changes and getting symptoms investigated as soon as possible.

But although her health battle will become the heart of her return storyline, Sam being Sam means trouble is never far behind. Her fear about the lump and the pressure she’s under will spill into other parts of her life, sparking clashes, stirring up old tensions and pulling her into situations that only complicate things further. It’s very clear that this quieter re-entry is not representative of what’s to come. Sam has always been unpredictable, and Walford is about to feel the full impact of her being back on the patch.

Fans familiar with her past will know that Sam rarely arrives without an agenda, and upcoming episodes will explore the emotional fallout of keeping her secret as well as the questionable decisions she makes along the way.

Her return also raises huge questions for the Mitchells. Phil has no idea she’s back. Jack hasn’t clocked her yet. And Walford being Walford, secrets never stay hidden for long. Once word gets out that Sam has returned,